This invention relates to the subject matter of U.S. Pat. No. 4,407,379 issued Oct. 9, 1983 the disclosure of which is hereby incorporated by reference.
One of the problems of making filling machines, especially for hard to handle substances, is that one cannot be assured when filling any one package that the weight is right. Therefore, it is often needed to add more to it (or remove material), also called "dribble fill". The question is, how to do this at high speed and high accuracy?
One approach has been shown in the above mentioned, U.S. Pat. No. 4,407,379 which allows containers (packages) to be weighed on-the-fly and their fill weight corrected. Disclosed herein is an improvement wherein a combination of weigh/dump cells, according to the invention are transported relative to package carrying cells, which also may be according to the invention, and used to assure that the packages are filled to the correct weight.
This invention contemplates the use of the electro-optical cells of the referenced patent in weigh dump receptacles such as are known in the art. The material is then transfered to the container and additional material added or removed if required.
More than one weigh dump cell can be used to fill any given container. Via the invention, the weigh dump receptacles and/or the containers can be in continuous motion for maximum speed and reliability (a major problem with current weigh dump systems which must generally stop).
A major advantage also results in that the containers themselves can also be weighed in such a system, allowing container tare weight to be accounted for and determining the extent of subsequent weigh receptacle dump or dribble operations to be performed.